Conventional anchors used in oil wells for supporting pumps or the like within the well casing incorporate a tubular anchor frame, a drag block for bearing against the walls of the casing to prevent rotative movement of the anchor frame while the anchor is being set and a plurality of slips having upper and lower feet mounted within a slip cage secured to the frame, each of the slips actuable by pairs of cones mounted on the frame to slide towards each other into anchoring position under the slip feet and force the slips outwardly into anchor supporting engagement with the walls of the casing.
Regular or conventional anchors are generally not suitable for wells that require a torque pump. Torque pumps will apply pressure directly to shear release screws of the anchors, through the slips, which torque could release the anchor prematurely.
Canadian Patent No. 1,274,470 of Weber issued Sep. 25, 1990 teaches an anchor which has a shear release mechanism and rotationally induced slip movement through use of a mandrel. The slips are driven into anchor supporting engagement by means of cams mounted on the mandrel surface.
Canadian Patent No. 973,473 of Young issued Aug. 26, 1975 describes and illustrates a slip design for an anchor which requires expanders similar to cones. This tool both sets and releases under tension.
Canadian Patent No. 704,201 of Conrad issued Feb. 23. 1965 teaches an anchor device which has a torque-operated setting mechanism and a tension operated secondary release mechanism.
Other patents of general background interest include Canadian Patent No. 653,892 of Clark et al issued Dec. 11, 1962, Canadian Patent No. 633,778 of Conrad issued Jan. 2, 1962, Canadian Patent No. 1,281,998 of Braddick issued Oct. 6, 1991 and Canadian Patent No. 1,255,584 of Scranton et al issued Jun. 13, 1989.
It is an object of the present invention to provide an anchor which operates in conjunction with either a tension or a torque-type pump in a well. It is a further object of the present invention to provide such an anchor which prevents the pipe string and stator from rotating or from moving up or down when the anchor is set in a well casing.